I'm mostly instinctive. I have an idea of what's coming up in the week, so I am aware Wednesday evening I'm out, so needs to be quick and easy. I also think about what veg or meat needs using up. Shopping list is a mix of specifics, so this week included tin foil, which I don't buy often, but don't tend to write down milk, as I know I get that every week. I usually buy meat and veg depending what's in season (I don't buy Peruvian asparagus or Kenyan beans) and on the shelves, but I have an overall idea of what I want. If I want to do something new, I might have a more focused shopping list.
We had a large, productive garden in my childhood, so we often had to deal with a glut of raspberries or runner beans or something, so we would end up with lots of meals with variations of the same vegetable (and at various points of the year, my mother saying we needed to eat up the freezer, which I find mystifying as an adult, too...)
I do use recipe books, but usually for inspiration than exact instructions. I can make a basic cake by just chucking butter, flour, etc together till it looks right, but a new baking recipe, I will measure. Yesterday, I did pastry for probably the first time in 3 years or do, so I did look up time and temperature for the oven as a reminder. I grew up with a Rayburn, which didn't always heat consistently, so I think that gave me an idea of how things could be adjusted and what things needed more accuracy. Also, I have travelled quite a bit, and learnt you can create makeshift ovens for cake and so on, when you're in the middle of nowhere, and you can end up with something very acceptable without it being a perfect 175degC. Millions of cooks before the mid-20th century wouldn't have had ovens with exact thermostats, so there's always a bit of leeway.
I agree with those who say you need to build experience to become instinctive.